IEEE 802.15
Harald Øverby
Outline
IEEE 802.15.1 – ”Bluetooth”
IEEE 802.15.3 – High data rate WPAN
IEEE 802.15.4 – Low data rate WPAN
References
Ganz et al., Multimedia Wireless
Networks
Siep, IEEE 802.15.1 Tutorial
Gandolfo, IEEE 802.15.3
Overview/Update
Barr, IEEE 802.15 TG3 and SG3a
Gutierrez, IEEE 802.15.4 Tutorial
Shellhammer, Tutorial on 802.15.2 draft
IEEE 802.15 - General
Wireless Personal Area Networks
(WPANs)
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
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Short Range
Low Power
Low Cost
Small Networks
Communication within a persons
operating space
IEEE 802.15.2
IEEE 802.15.2


Coexistence
between
802.15 and
802.11
Predefined
traffic
management
rules for
coexistence
Outline
IEEE 802.15.1 – ”Bluetooth”
IEEE 802.15.3 – High data rate WPAN
IEEE 802.15.4 – Low data rate WPAN
IEEE 802.15.1 - General
Adopted the Bluetooth MAC and PHY
specifications
IEEE 802.15.1 and Bluetooth are almost
identical regarding physical layer,
baseband, link manager, logical link
control and apdation protocol, and host
control interface
IEEE 802.15.1 – Usage Scen.
IEEE 802.15.1 – Global setting
Outline
IEEE 802.15.1 – ”Bluetooth”
IEEE 802.15.3 – High data rate WPAN
IEEE 802.15.4 – Low data rate WPAN
IEEE 802.15.3 - Overview
High data rate WPAN
Potential future standard
Motivation: The need for higher
bandwidths currently supported with
802.15.1


100 Mpbs within 10 meter
400 Mpbs within 5 meter
Data, High quality TV, Home cinema
IEEE 802.15.3 - Overview
Dynamic topology
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Mobile devices often join and leave the
piconet
Short connection times
High spatial capacity
Multiple Power Management modes
Secure Network
IEEE 802.15.3 - Overview
Based on piconets
Data Devices (DEV) establish peer-topeer communication
Includes also a Piconet Coordinator
(PNC)
IEEE 802.15.3 - Topology
IEEE 802.15.3 - Superframe
IEEE 802.15.3 - Beacon
Beacon
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Control information
Allocates GTS
Synchronization
IEEE 802.15.3 - CAP
CAP
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Allows contention via CSMA/CD
Command exchange between DEV and
PNC
File transfers from DEV without request
IEEE 802.15.3 - CFP
CFP
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Time slot allocation specified in the beacon
Reserved bandwidth for DEV
MTS: Command, GTS: Data
IEEE 802.15.3 - GTS
GTS reservation

DEV sends a Channel Time Request (CTR)
to PNC
 Isochronous data: number and duration of
slot(s)
 Asynchronous data: Total amount of data


PNC allocates GTSs to DEV via CTA
DEV is responsible of utilizing allocated
GTSs
IEEE 802.15.3
Just to make sure...
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
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Isochronous signals: Significant instants
(e.g. Start of a bit) have the same duration
Anisochronous signals: Significant instants
(e.g. Start of a bit) do not have the same
duration
More accurate to use anisochronous
instead of asynchronous when talking
about a single signal
IEEE 802.15.3 - GTS
Two types of GTSs

Dynamic GTS
 Location within a superframe may change
 PNC can optimize channel utilization

Pseudostatic GTS
 Only for isochronous data
 Fixed location within a superframe
 May be changed, but only after a series of
notitications to the DEV
IEEE 802.15.3
IEEE 802.15.3
Starting a piconet


DEV scans the for the best channel and
sends out beacons -> the DEV becomes
PNC
If no channels available: Establishes a child
or neighbor piconet instead
 Requests a private GTS from parent PNC
 All communication takes place within assigned
GTS
IEEE 802.15.3 - QoS
QoS
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
IEEE 802.15.3 supports both synchronous
and asynchronous data
CAP offers only best-effort
The PNC will allocate resources in the CFP
 Through admission control
 Synchronous data: Based on number of time
slots per superframe, duration of slot, priority
and GTS type
IEEE 802.15.3 - QoS
 Asynchronous data: Based on total data and
priority

After performing admission control, GTSs
may be allocated
Outline
IEEE 802.15.1 – ”Bluetooth”
IEEE 802.15.3 – High data rate WPAN
IEEE 802.15.4 – Low data rate WPAN
IEEE 802.15.4 - Overview
Low Rate WPAN (LR-WPAN)
Simple
Low cost
Low power consumption
E.g. Sensor networks
Data rates: 20-250 kbps
IEEE 802.15.4 – Protocol stack
IEEE 802.15.4 - DEVs
2 or more DEVs form a PAN
2 different types of DEVs

Full functional Device (FFD)
 Coordinator and simple node
 Any topology
 Talks to any device

Reduced Functional Device (RFD)
 Simple node only, either source or desination
 Star topology only
 Talks to network coordinator only
IEEE 802.15.4 - Star
IEEE 802.15.4 – Peer-to-Peer
IEEE 802.15.4 - Combined
IEEE 802.15.4 - QoS
QoS – 3 traffic types
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Periodic data: e.g. Sensor data
Intermittent data: generated once a while,
e.g. Ligth witch traffic
Repetitive low latency data: E.g. Mouse
device traffic
Sophisticated QoS mechanisms may
reside in upper layers
Thats all folks - Summary
IEEE 802.15.1: Bluetooth
IEEE 802.15.3: High data rate WPAN
IEEE 802.15.4: Low data rate WPAN